Does this pump come with a new washer fluid reservoir or just the pump?

Pump assembly only. You'll reuse your existing reservoir — the pump mounts inside it.

What tools do I need to swap this in?

Basic hand tools and the ability to disconnect the electrical connector and fluid lines. No special tools required — straightforward swap for anyone comfortable working under the hood.

Will this work if my lines are cracked or old?

The pump itself will work fine, but cracked lines will leak. Inspect your washer hoses during installation — if they're brittle or damaged, plan to replace them at the same time for a clean job.